“It had an ugly sound,” I answered.

“Yes. There’s blackmail in it, or I am much mistaken.”

“And who is the blackmailer?”

“Well, it must be the creature who lives in the only comfortable room in the place, and has her photograph above his fireplace. Upon my word, Watson, there is something very attractive about that livid face at the window, and I would not have missed the case for worlds.”

“You have a theory?”

“Yes, a provisional one. But I shall be surprised if it does not turn out to be correct. This woman’s first husband is in that cottage.”

“Why do you think so?”